In wireless communication systems, multiple-input and multiple-output (MIMO) refers to use of multiple antennas at both a transmitter and a receiver to improve communication performance. Multi-user MIMO (MU-MIMO) refers to a MIMO system in which a base station or an access point transmits data streams simultaneously to a plurality of user equipments. To enhance the communication capabilities of all the terminals, MU-MIMO applies an extended version of space-division multiple access (SDMA) to allow multiple transmitters to send separate signals and multiple receivers to receive separate signals simultaneously in the same band.